Agreed. I've long been a proponent of the 75% rule - I think it states something like that in most manuals. They usually recommend that you move your 'main out' volumes up to around 75%, then do the rest on your PA or amp.

I even extend that to the individual channel sliders on my Pa1Xpro. With sliders, given that you have 'on the fly' control over the mix, you can adjust say, a horn riff, to further back or further forward, or even mute it altogether, in the mix. Leave yourself some flexibility.

Want to boost the solo? Use your 25% headroom. You can't do that if everything is flat out from the get go.